Another great video by @ConquerAging
He posits that an optimal HBA1c value is between 5-6. Specifically, he believes it should be between 5-5.3 as it is in youth. I find it interesting that pre-diabetes starts at 5.6, but the normal value for 50-year-olds is 5.8. So, are all 58 year olds supposed to be pre-diabetic?
A very quick and interesting video!
What was his problem with lower than 5.0?
If you go below 5.0, you experience higher all-cause mortality. It’s in the video.
I feel like some of his stuff is TOO population based epidemiological… I mean, this looks like some of the cholesterol stuff, where lower cholesterol was linked with higher all cause mortality…. I think some of that is due to disease states, etc.… I am in bed so I will watch the video this weekend and then report back. I really really like Michael Lustgarten though. He offers consultations and blood work analysis, out of ALL the people available that do that, I would probably have him do it more than anyone, including Attia, etc…
Well, if your HBA1c goes down too much, you experience hypoglycemia which is not good for you. Having experienced it myself, it feels like you’re having a heart attack. So, I agree that 5-5.3 is optimal.
Without having watched the video, are the studies he is using based on observational data? If so, I would completely disregard the result as it is once again a result of reverse causality.
The video is less than 5 minutes long. Give it a watch. 
I’ll check out the referenced studies.
Study subjects comprised 6,027 community-dwelling individuals who were recruited to a population-based longitudinal genetic epidemiological study.
Here we present a deep learning model the uses vital signs and lab tests contained within the EMR of Mount Sinai Health System (MSHS) to predict chronological age. The model is trained on 377,686 EMR from patients of ages 18–85 years old. The discrepancy between the predicted and recorded chronological age is then used as a proxy to estimate physiological age.
We systematically searched Medline, Embase, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews and Web of Science databases, from inception to July 2016, for observational studies addressing the association of HbA1c levels with mortality and cardiovascular outcomes.
So as I expected, it’s 100% based on observational studies with typical U-shaped mortality curves which can be seen for cholesterol and BMI aswell.
It is tempting to spread this video in the keto cycles though.
I still think 5-5.3 is a great target to aim for.
I would rather stay as far away from being pre-diabetic as I can.
I am someone who normally has an HbA1c below 5. I think there are two reasons for this. One is that I drink a lot of alcohol from time to time and the other is that I often have large doses of melatonin.
This meta analysis by Delpino suggests an improvement in insulin sensitivity with melatonin up to 10mg dosing, however, a more recent study in diabetics showed a decrease in insulin sensitivity with melatonin of 10 mg.
https://www.clinicalnutritionjournal.com/article/S0261-5614(21)00294-6/fulltext
Alcohol usage definitely drives down HbA1c
Melatonin also lowers blood glucose.
You’re going to wreck your circadian rhythm and possibly brain with that dose though.
So what does my 500mg dose do?
It wont help with your circadian rhythm at least.
I take varying amounts of melatonin, but always during the early morning. One thing that happens during sleep is that the blood pressure goes down enabling CSF with a higher concentration of melatonin to wash through the brain. I personally think (partially based upon personal experience) that a high serum level of melatonin at night is good for the brain, but you could argue that it damages my perceptions of what is good.
Melatonin has a considerable number of effects, but I really don’t think it can be argued that a 10mg dose harms the brain.
Taken at the wrong time it will disrupt the circadian rhythm more precisely it will cause the sympathetic nervous system to dominate at an unhelpful time.
I take melatonin for sleep and circadian rhythm effects.
(1) a lower dose (0.3 mg - 1 mg), is superior than higher dosages for sleep.
(2) people like huberman say higher dosages are bad because they inhibit puberty, and therefore have effects on hormones in the brain.
I have not done more research than this, but since I take it for sleep I have no reason to take higher dosages nor research whether higher dosages are bad for the brain.
Is there any evidence melatonin has a negative effect on adults?
I don’t know, I hope the people taking mega doses do.
Small doses are pretty safe as far as I know.